以再生水为补水的景观水体水华爆发特征调查和药剂应急控藻效果评价

采用现场调查和实验室验证的方法，对以再生水为景观补水的水华优势藻进行了分析。2年的现场调查表明，再生水在条件适合时极易发生水华，且水华的优势藻以小球藻为主。在实验室针对小球藻和铜绿微囊藻进行了竞争生长实验研究，在再生水的氮磷浓度范围内小球藻生长快于铜绿微囊藻，这也验证了再生水作为景观水补水时小球藻是优势藻现场调查结论。针对水华爆发初期和水华爆发验证时2种条件，比较研究了4种以化学成分为主的抑藻药剂对以小球藻为水华特征藻的控藻效果。结果表明，这4种药剂对水华的控制均具有一定的效果，并且水华初期实施药剂抑藻，药剂投加少，且效果好。对4种药剂进行急性毒性实验，只有S2一种药剂在安全浓度时对水华爆发初期有抑藻效果。     

10种药物材料对铜绿微囊藻的抑制作用

为筛选抑制铜绿微囊藻生长的有效药物材料,确定其最佳的抑藻浓度,采用叶绿素a检测法来确定铜绿微囊藻的生物量,从而对10种药物材料的作用效果进行了定性研究,并采用二倍稀释法对筛选出的8种药物材料进行了最佳抑藻浓度的测定。大黄、黄连、土槿皮、蜜桔皮、马水桔皮、蜜柚皮、铁观音、大蒜等药物材料能有效抑制铜绿微囊藻的生长;大麦茶、仙鹤草不能抑制铜绿微囊藻的生长。当蜜桔皮、蜜柚皮水提液质量浓度大于6.25g/L,马水桔皮水提液质量浓度大于3.13g/L,铁观音、大黄浸提液质量浓度大于5.000g/L,土槿皮、黄连提取物浸提液质量浓度大于2.500g/L时对铜绿微囊藻的生长具有有效的抑制作用,且随着各浸提液浓度的增加,其抑制效果呈上升趋势;而大蒜液质量浓度大于5.000g/L时能使铜绿微囊藻维持在初始水平。将各材料抑藻浓度设定在以上浓度时较为合理。研究结果为水产养殖治理蓝藻以及控制蓝藻药物进一步的研发提供了参考。     

影响钝顶螺旋藻固碳的环境因子优化

为了提高钝顶螺旋藻生长过程中的固碳速率,从CO2浓度、温度和光周期3个主要环境因子进行优化。实验结果表明,钝顶螺旋藻在2 L三角瓶中培养时,最佳培养条件为10%CO2,温度30℃,光周期16/8。最佳培养条件下,钝顶螺旋藻对数生长期内比生长速率与固碳速率均达到峰值0.512 d-1和42.506 mg/(L.h)。此外,钝顶螺旋藻的底物消耗表明培养液中的N、P足量,其初始添加量可以满足藻体的生长需要;生长过程中补加10%CO2一方面补充钝顶螺旋藻可吸收碳源,另一方面有利于缓解培养液pH升高对藻生长的影响。     

湘江株洲段镉污染动态模拟与情景分析

本研究利用美国环境保护局(USEPA)推荐的WASP水质分析模拟软件,对湘江株洲段2009年的镉浓度进行动态模拟,并进行总量控制的情景分析。对水文条件变化和源强变化2种情景下的河道镉浓度进行了预测。结果表明,WASP模型能较好重现镉浓度的时间变化规律。情景分析表明,水文条件和源强条件对镉浓度的影响在霞湾和马家河断面较为明显,且在枯水月份表现得更为明显。     

不同运行条件对微生物燃料电池产电性能的影响

以双室微生物燃料电池为研究对象,改变活性污泥MLSS值、营养物质的量、营养物质种类、温度等运行条件,测量24 h内COD值、细菌数目和电压值,进而研究不同运行条件对微生物燃料电池运行初期产电性能的影响。结果表明:在其他同等条件下,只改变MLSS值时,MLSS值越大,产电性能愈佳,只改变葡萄糖浓度时,当葡萄糖浓度为60 mg/m L时,产电性能最佳,最大电压和功率密度可达224.8 m V和505 m W/m3,只改变营养物质种类时,当加入低糖和C源营养物质时,产电性能较佳,只改变运行温度,当温度为37℃时,产电性能最佳,最大电压和功率密度可达231.5 m V和535 m W/m3;改变上述条件时,细菌数目与MFC的产电性能呈显著正相关关系。     

壳聚糖在固定化光合细菌处理染料活性艳红X-3B中的应用研究

采用海藻酸钠对光合细菌进行包埋,并在固定化过程中加入壳聚糖,研究添加了壳聚糖的固定化细胞在不同条件下对活性艳红X-3B的脱色效果及其降解动力学.实验结果表明,在厌氧条件下,X-3B的脱色效果较好;染料浓度在30～300 mg/L之间变化时,厌氧降解动力学方程均符合一级动力学方程;降解速率与染料初始浓度之间关系符合Michaelis-Menten方程,反应动力学参数Km=374.96 mg/L,Vmax=7.53 mg/L·h.振荡有利于脱色并使半衰期缩短;固定化小球可重复使用.     

水力空化耦合电解抑藻工艺性能的初步研究

采用水力空化与电解耦合的工艺去除水体中的藻类。初步探索了包括空化管径和电解时间在内的处理工艺参数，改善了处理装置结构。试验选用天然水体优势藻种——铜绿微囊藻和水华鱼腥藻为研究对象，在优化后的水力空化条件下，水头压力0.33 MPa，电流密度为2.13 mA/cm²，处理10 L密度为3.0×106 mL^-1的铜绿微囊藻藻液。结果表明，该装置具有显著的抑藻效果，处理30 min的水样在处理后培养3 d可以达到76.9%的抑藻率，4 d后抑藻率上升到到97.5%。而对藻液分别进行单独空化30 min和单独电解30 min后培养4 d的抑藻率分别为27.7%和27.8%，表明空化耦合电解具有协同作用。通过比较该装置对不同藻种以及处于不同生长阶段的藻种的处理效果，发现装置对铜绿微囊藻的抑藻率显著优于水华鱼腥藻；对于铜绿微囊藻而言，处于对数生长期的藻细胞比稳定生长期更易被除去。     

柑橘类果皮水提液对铜绿微囊藻生长的影响

研究了柑橘类果皮水提液对铜绿微囊藻生长的影响。采用二倍稀释法将儿种柑橘类果皮水提液分成7个浓度组,每组3个平行,在温度(25.0±0.5)℃,光照强度3000 l×下培养铜绿微囊藻。结果表明,柑橘类果皮水提液能有效抑制铜绿微囊藻的生长,且随着浓度的增加其抑藻作用增强。其中,蜜桔皮、马水桔皮、蜜柚皮水提液质量浓度在6.25、3.13、6.25g/L时对铜绿微囊藻的生长具有极显著的抑制作用(P0.01)。实际应用时,柑橘类果皮水提液质量浓度为6.25g/L时较为合理。柑橘类果皮中存在一种或几种能有效抑制铜绿微囊藻叶绿素a合成的物质,从而抑制铜绿微囊藻的生长,此类物质在高温处理下仍能保持一定的抑藻活性,这为控制蓝藻药物的研发提供了一定参考。     

废水水质均和时间的盈亏计算法

工业废水的特征之一是所含污染物的种类相对稳定,流量、污染物浓度随时间而变化,往往给下一步处理带来困难。为了改善处理工序的工作条件,必须对废水的浓度进行均和。均和程度的依据是处理工序所要求的污染     

高效复合菌处理高浓度食品污水的试验

以食品污水作为培养基，对高效复合菌进行了富集培养。用培养液对高浓度食品污水作降解试验，并对活性污泥作减容试验，结果表明：在好氧条件下，培养液在污水中的投加量为5‰时，反应12h后，污水的CODcr去除率为52％；在静沉下，活性污泥中培养液投加量为5％时，反应6h后，污泥体积可减少70％。     

Effects of a surfactant (FFD-6) on Scenedesmus morphology and growth under different nutrient conditions

Surfactants are man-made compounds that are meanwhile omnipresent in the environment, but environmental concentrations of surfactants are such that they are thought to have little risk for aquatic systems. The major anionic surfactants currently on the global market are linear alkylbenzene sulfonates (LAS), a class where the commercially available FFD-6 belongs to. The hypothesis was tested that sublethal effects of FFD-6, i.e. the morphological effect of colony formation in the common test alga Scenedesmus obliquus, occurs at a concentration lower than the no-observed-effect concentrations for endpoints commonly used in regulatory toxicity testing with algae. The surfactant FFD-6 induced colonies in Scenedesmus at concentrations a few orders of magnitude lower (i.e. between 0.001 and 0.01 g l-1) than at which growth inhibition was observed (i.e. between 1 and 10g l -1). Growth rates were lowest for Scenedesmus grown in P-limited medium, intermediate for algae reared in N-limited medium and highest for algae cultured in non-limited standard medium. Growth inhibition due to FFD-6 was similar for non-limited and nutrient-limited Scenedesmus, but colony formation was stronger in non-limited Scenedesmus than in nutrient limited cultures. The colony inducing effect of the surfactant FFD-6 on Scenedesmus occurs at much lower concentrations than growth inhibition and might affect species interactions, the survival of species and the energy flow along the food chain.     

Zinc acclimation and its effect on the zinc tolerance of Raphidocelis subcapitata and Chlorella vulgaris in laboratory experiments.

The effect of zinc acclimation of Raphidocelis subcapitata (syn. Selenastrum capricornutum) and Chlorella vulgaris on their sensitivity towards this metal was examined in a series of laboratory experiments. These two commonly used algal species were acclimated to 65 microg Zn/l and changes in zinc tolerance were monitored using standard growth inhibition tests. The chemically defined ISO medium was used as a control culture medium. Both species demonstrated a maximum increase in zinc tolerance of a factor of 3 after 100 days of acclimation. Shifts in the shape of the concentration-response curve due to acclimation were observed for R. subcapitata. Compared to non-acclimated algae, acclimated R. subcapitata exhibited higher growth rates in all zinc treatments as well as in the controls. This suggests that the use of ISO-medium results in sub-optimal growth due to zinc deficiency. These effects could not be demonstrated for C. vulgaris. The zinc tolerance of both species decreased significantly one week after returning the acclimated algae to control (ISO) medium. 72hEC50 values based on growth rate were two to four times higher than those calculated using biomass measurements. Algal toxicity test results, particularly if used for metal risk assessments, must not be conducted using nutrient deficient media.     

The effects of crude and fuel oils on the growth, chlorophyll 'a' content and dry matter production of a green alga Scenedesmus quadricauda (Turp.) bréb

The growth of Scenedesmus quadricauda algae in a batch culture was examined in the presence of crude oil and fuel oil, added to the cultivation medium in the form of a water-soluble fraction (WSF), water extract (WE) and oil-water dispersion (OWD). On applying various concentrations of oils, a decrease in the number of cells, dry matter and chlorophyll 'a' production, with respect to the cell population, was observed. The extent of this decrease depended on the kind and concentration of the soluble and dispersed hydrocarbon fractions and on the proportions in which these occurred in the culture medium. On the other hand, the water extracts of both oils stimulated dry mass and chlorophyll 'a' content with respect to a single cell. This effect was accompanied by increased size of the algal cells. The WSF, WE and OWD of fuel oil, prepared from 200, 50 and 1 cm(3) of oil per dm(3) of BBM medium, respectively, had a similar inhibitory effect, which points to the dominant role of oil dispersion in the reduction of algal growth. Chemical analysis of the water extracts of fuel oil revealed the presence of 35 hydrocarbons of various kinds, mainly n-alkanes and polycyclic aromatic hydrocarbons.     

Temporal changes in the toxicity of pentachlorophenol to Chlorella pyrenidosa algae

The toxicity of pentachlorophenol (PCP) on Chlorella pyrenidosa algae was investigated with specific attention given to possible variation of toxic effects with time. A concentration-effect relationship was observed in which there was significant inhibition of PCP on cell density and chlorophyll A content. The inhibition rate of PCP on cell density was dependent on exposure time. The IC50 values after exposure times of 2, 4 and 6 days for cell growth were 4.18 +/- 0.49, 3.49 +/- 0.40 and 3.30 +/- 0.26 mg/L, respectively. There was also inhibition of chlorophyll A production, which appeared to increase marginally with exposure time for a given concentration of PCP. The corresponding IC50 values on day 2, 4 and 6 were 2.30 +/- 0.12, 2.63 +/- 0.38 and 3.30 +/- 0.34 mg/L, respectively. The effect of PCP on nitrate reductase (NR), was first stimulation followed by an inhibition phase. It is postulated that the observed temporal changes in the activity of nitrate reductase (NR) may occur through the addition or loss of phosphorus in the NR protein.     

城市污水厂污泥替代营养盐培养海水小球藻的研究

为了城市污水厂污泥的资源化利用,对污泥替代F/2培养基培养海水小球藻(Chlorella pacifica)进行了研究。首先采用研磨-离心法制备污泥抽提液,将其与F/2培养基按体积比7∶3混合,接种微藻并在优化的条件下培养6 d,逐日测定混合液中无机氮、磷的浓度,培养结束后测定微藻生物量以及干藻中蛋白质、氨基酸和重金属含量。结果表明,将微藻在最佳条件下培养6 d后,混合液中PO34--P、NO2--N、NH4+-N和NO3--N的吸收率分别达到97.32%、96.72%、97.55%和78.13%;与F/2培养基对照组相比,混合液中微藻的生物量增加11.5%;蛋白质、必需氨基酸和非必需氨基酸的含量变化不大。另外,干藻中的重金属含量符合饲料行业标准的要求。     

The impact of aluminium on green algae isolated from two hydrochemically different headwater streams, Bavaria, Germany

Two strains of green algae (Scenedesmus sp. and Chlorella sp.) have been isolated from two headwater streams differing in stream chemistry (Eger river: acidic, low alkalinity; Püttlach river: slightly alkaline, high alkalinity). In this study the growth response of these indigenous algae to increased concentrations of aluminium (Al) is investigated. A semi-continuous culture technique was used for Al-toxicity studies. Algal response was determined by calculating growth rates from turbidity and cell counts. Those Al-species which are well known to be toxic were estimated by equilibrium calculations using the WATEQ computer program (Truesdall & Jones, 1973). The pH-value of the culture media was usually pH=5, except for one of the test series. Tested concentrations ranged from c=4 to 220 micromol litre(-1). The isolated strains of green algae were highly sensitive to increased Al-concentrations. The strain isolated from the Püttlach river was more sensitive than the Eger river algae. A total growth inhibition occurs at Al-concentrations of c=4 micromol litre(-1) if the whole Al was added at once. If Al was added gradually into the growth media the response of the algae was delayed. This is due to Al-enrichment in cells. In our long term toxicity studies, growth inhibition occurs even at nearly neutral pH-conditions (pH=6.5) although Al toxicity is expected at pH-values less than pH=5.5. This new result confirms the need of long-term studies in continuous cultures under simulated natural conditions. This might be the only way to achieve valid conclusions about the fate and the toxicity of environmental pollutants.     

植物对氮、磷去除效果及克藻效应的研究

于夏季，在实验室和莫愁湖现场，开展了苦草和美人蕉对氮、磷去除效果及克藻效应的研究，结果表明，无论是在现场还是实验室，苦草和美人蕉对总氮、总磷都有明显的去除效果，且随着时间的增加，去除率也随之增大。在实验与现场条件，美人蕉与苦草对总氮和总磷的去除率之间没有显著差异。苦草和美人蕉都对蛋白核小球藻和铜绿微囊藻两种藻类表现出显著的抑制作用，但在实验与现场条件下，美人蕉和苦草对两种藻类的抑制效应存在着显著差异，而对于藻种则二者均表现出一定的选择性抑制作用。     

Combined effect of polystyrene plastics and triphenyltin chloride on the green algae Chlorella pyrenoidosa

The combined effect of polystyrene (PS) particles and triphenyltin chloride (TPTCl) to the green algae Chlorella pyrenoidosa was studied. The 96 h IC₅₀ of TPTCl to the green algae C. pyrenoidosa was 30.64 μg/L. The toxicity of PS particles to C. pyrenoidosa was size-dependent, with the 96 h IC₅₀ at 9.10 mg/L for 0.55 μm PS but no toxicity observed for 5.0 μm PS. The exposure to 0.55 μm PS led to damage on structure of algal cells, which could in turn cause inhibition on photosynthesis and population growth of the green algae. TPTCl concentrations in test medium were lowered by 15–19% at presence of 0.55 μm PS particles, indicating a reduced bioavailability of TPTCl. In spite of this reduced bioavailability, the presence of PS increased the toxicity of TPTCl, which might be attributed to facilitated uptake of TPTCl by the green algae after the damage of cell structure. The overall results of the present study provided important information on the effect of PS on the bioavailability and toxicity of TPTCl to phytoplankton species.

     

Studies on nitric oxide (NO) formation by the green alga Scenedesmus obliquus and the diazotrophic cyanobacterium Anabaena doliolum.

This study provides preliminary evidence that NO production could be a general attribute of algae. Anabaena doliolum was found to be a better NO producer than Scenedesmus and Synechoccocus. Experiments conducted with inhibitors of photosynthesis (DCMU), ATP synthesis (DCCD), and the uncoupler (2,4-DNP) and its analog arsenate clearly revealed that inhibition of nitrite assimilation through the blockage of nitrite reductase (NiR) is primarily responsible for NO emission. A linear relationship between nitrite concentration in the culture medium and NO in the exhaust gas supports the view that accumulation of nitrite is responsible for NO formation. A failure of Scenedesmus, grown in the medium substituted with W for Mo, to produce either NO/NO-2 in light or a 'light-off' peak, and a resumption of these activities upon the addition of Mo proved beyond doubt that a functional nitrate reductase (NR) is necessary for the production of nitrite and NO by algae grown on nitrate as the nitrogen source. Moreover, the appearance of a NO peak immediately after nitrite supplementation under dark conditions in W-substituted cultures with or without glucose ruled out an enzymatic role of NR in NO emission.     

Germination and seedling growth of the water cress Rorippa sp. exposed to the chelant [S,S]-EDDS

With the implementation of the new EU environmental framework directives, high tier risk assessments of chemicals will be increasingly needed. For high production chemicals, additional tests will complement the standard battery for aquatic toxicity assessments (daphnids, algae, and fish). In the context of a new chemical notification at the European Union level, we have developed a seed germination and root elongation toxicity test with the freshwater aquatic plant Rorippa nasturtium-aquaticum (water cress) to confirm the low environmental risk of the chelant [S,S]-EDDS. A 14 day semi-static growth inhibition test was conducted with daily renewal of the test solution. No concentration related inhibition was found on the basis of any of the criteria investigated, i.e., time and extent of germination, biomass, number of leaves, stalk and root lengths. The no-observed effect concentration was considered to be >or=387 mg SS-EDDS/l. Although germination was selected as an appropriate endpoint to assess the effect of a chelant on an aquatic plant (other endpoints would have been dependant on essential metals that are chelated in standard culture tests), the absence of dose related effects requires further tests with higher exposure concentrations and/or other toxicant(s) to assess the validity of the test as a general tool for aquatic risk assessment.